Method and Installation for the Production of Pellets from Biomass in a Pelletizing Press for Use as Fuel in Furnaces

ABSTRACT

A method and installation for production of pellets from processed biomass in a pelletizing press for use as fuel in furnaces, in which the biomass includes cellulose- and/or lignocelluloses-containing fibers, shavings or chips with or without a binder and/or additives and the biomass after processing is fed with a metering device to a pelletizing press. The biomass is separated with a breaker device right before the pelletizing press. Biomass is introduced to a metering device, which includes a spreading device and an endless shaping belt lying beneath it in the direction of fall, in which a mat with an essentially uniform weight per unit area is formed in the metering device on the shaping belt and the metering device feeds the mat to a breaker device in front of the pelletizing press, in which the biomass is separated by the breaker device.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

Germany Priority Application DE 10 2009 016 469.3, filed Apr. 13, 2009 including the specification, drawings, claims and abstract, is incorporated herein by reference in its entirety.

BACKGROUND

1. Field of Embodiments

The embodiments concern a method for the production of pellets from processed biomass in a pelletizing press for use as fuel in furnaces according and an installation for the production of pellets from processed biomass in a pelletizing press for use as fuel in furnaces.

2. Description of Related Art

Production of pellets, also called briquettes or granulate, from ground products or compacted and/or melted material is already long known. Briquette presses compacted material and shaped it into furnace briquettes between two rolls, one or both being designed as dies. Pelletization with extruders and perforated disks, optionally with subsequent cutting devices, is also adequately known in the plastics industry or in the industry that processes animal feed. Production of pellets from ground biomass, like sawdust, dust or the like, is also already adequately known and is propagated in the field of renewable energy as a future technology for climate protection, especially in Europe.

Biomass is now stored after processing (size reduction, screening, drying, etc.) in biomass bunkers and then discharged with metering devices and fed to a pelletizing press. Screw conveyors are ordinarily used as metering devices, which, however, are not suitable for simultaneously supplying several large pelletizing presses with constant material flow. Consequently, at least one pelletizing press, generally an pan-grinder press with annular dies or a double-roll press, must be arranged per screw conveyor. As an alternative in small installations (production for home or community use) direct feed to the pelletizing press can be provided, in which case a metering device is generally always provided for the pelletizing press but is refilled by hand.

It is inherent to screw conveyors that the biomass, which has already been compacted to a certain degree by its own weight during storage in the biomass bunker, must be additionally compacted during feed and fed to the pelletizing press. However, material agglomerations hamper constant feed to the pelletizing presses, since in the extreme case they emerge piecewise from the feed. They can even lead to problems in the inlet of pelletizing presses or to a reduction in maximum throughput per hour, if the material agglomerations can no longer be reduced or reduced only with difficulty by the pelletizing presses and, for example, block the inlet of the pelletizing press because of their size and hamper or even prevent inflow of biomass into the press gap. At the same time, piecewise feed ensures non-uniform feeding of the pelletizing press, which becomes noticeable, depending on the type of pelletizing press, in increased wear or energy costs, if irregular drive or compaction forces must be supplied with energy or holding devices or storage facilities are overloaded.

Another problem is the separation of the biomass in the biomass bunker or during metering to the pelletizing press. Through feeding the problem arises that so-called nests are formed of uniform material, for example, dust nests or coarse nests. However, an optimal pellet and its production are characterized in particular by the fact that equal amounts of fine and coarse fractions are present in one pellet, which can mutually bond to each other.

During industrial production planning the additional problem arises that during enlargement of a double-roll press or pan-grinder press the feeding screw conveyor must be made larger by an exaggerated factor in order to permit proper feeding, or several screw conveyors must be arranged parallel for a large pelletizing press. The failure probability is increased significantly in such solutions and high acquisition costs arise for process engineering, especially for control and regulation engineering. If only one metering device fails, the entire installation must be shut down, since otherwise partial areas of the pelletizing press would operate without material, which causes increased wear.

SUMMARY

The embodiments concern a method for the production of pellets from processed biomass in a pelletizing press for use as fuel in furnaces, in which the biomass includes cellulose- and/or lignocellulose-containing fibers, shavings or chips with or without a binder and/or additives and the biomass after processing is fed with a metering device to a pelletizing press. The embodiments also concern an installation for the production of pellets from processed biomass in a pelletizing press for use as fuel in furnaces, in which the biomass includes cellulose- and/or lignocellulose-containing fibers, shavings or chips with or without a binder and/or additives and a metering device is arranged for the pelletizing press.

According to one embodiment, a method for the production of pellets from processed biomass in a pelletizing press for use as fuel in furnaces, in which the biomass includes cellulose- and/or lignocellulose-containing fibers, shavings or chips with or without a binder and/or additives and the biomass after processing is fed with a metering device to a pelletizing press. The biomass is separated directly before the pelletizing press with a breaker device.

According to another embodiment, an installation for the production of pellets from processed biomass in a pelletizing press for use as fuel in furnaces, in which the biomass includes cellulose- and/or lignocellulose-containing fibers, shavings or chips with or without a binder and/or additives and a metering device is arranged for the pelletizing press. For the separation of the biomass a breaker device is arranged in front of the pelletizing press in the direction of production.

According to yet another embodiment, a method for producing pellets from processed biomass in a pelletizing press for use as fuel in furnaces. The method comprises the steps of: processing the biomass; feeding the biomass to the pelletizing press with a metering device; and separating the biomass with a breaker device directly before feeding the biomass to the pelletizing press. The biomass includes cellulose- and/or lignocelluloses-containing fibers, shavings, or chips.

According to yet another embodiment, an installation for production of pellets from processed biomass for use as fuel in furnaces, in which the biomass includes cellulose- and/or lignocelluloses-containing fibers, shavings, or chips. The installation comprises a pelletizing press; a metering device arranged for the pelletizing press; and a breaker device arranged in front of the pelletizing press in a direction of production. The breaker device is configured to separate the biomass.

A method for optimizing a uniform feed of biomass to a pelletizing press is devised, avoiding the aforementioned drawbacks. An installation for execution of the method but also an independent installation is also devised, which permits optimal, uniform and preferably unseparated feed of processed biomass to pelletizing presses.

According to one exemplary embodiment or variant, the task for the method and installation includes ensuring continuous, optimal, uniform and unseparated feed of a pelletizing press over an arbitrarily large width.

According to another embodiment or variant, the method includes that the biomass is introduced to a metering device that includes a control device and an endless moving conveyor lying beneath it in the direction of fall, in which a mat with an essentially uniform weight per unit area is formed on the shaping belt in the metering device and the metering device feeds the mat to a breaker device in front of a pelletizing press, in which the breaker device separates the biomass.

The solution for another exemplary and variant of an installation includes the fact that a control device and an endless shaping belt lying beneath it in the direction of fall is arranged as a metering device to form a mat with essentially uniform weight per unit area and that a breaker device is arranged to separate the mat.

Additional advantageous measures and embodiments will become apparent from the claims and the following description of the drawings. It is to be understood, however, that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the embodiments as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present embodiments will become apparent from the following description, appended claims, and the accompanying exemplary embodiments shown in the drawings, which are briefly described below.

FIG. 1 is a schematic of an installation for the production of pellets after the processing of biomass and storage of the biomass in a biomass bunker and metered feed of the biomass to a pelletizing press with an exemplary breaker device.

FIG. 2 is a schematic of an alternative metering device for the pelletizing press of FIG. 1.

FIG. 3 is an enlarged view of a breaker device included in the metering device of FIG. 1 or 2.

FIG. 4 is an enlarged view of another breaker device that is included after the metering device of FIG. 2.

FIG. 5 is an enlarged view of exemplary breaker rolls in spoked or toothed form.

FIG. 6 is a schematic of another installation for the production of pellets with a preferred exemplary pelletizing press with pan-grinder rollers lying on the outside on a rotating annular die and optimal distribution of the biomass over the length and width of the pelletizing press by a metering device with a spreading device and a shaping belt and a breaker device arranged in the direction of fall.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Presently preferred embodiments are illustrated in the drawings. An effort has been made to use the same numbers throughout the drawings to refer to the same or like parts.

The process of production is presented as follows according to FIGS. 1 and 2. According to FIG. 1 the biomass 1 is discharged from a biomass bunker 3. This can occur with intermediate feed or directly with the metering device 4, which is designed according to FIG. 1 as a metering screw 19. The biomass 1 can be treated in the metering screw 19, as required, with steam by a steam treatment device 13 or also examined at an intermediate station for defective sites, defined by foreign objects hazardous for a pelletizing press 2. In the discharge area the biomass 1 falls out of the metering screw 19 and is now separated by means of a breaker device 5. The loosening can occur with one or more rolls, in which in this example the pelletizing press 2 is arranged in the subsequent direction of fall after separation by the breaker device 5, in this example as a two-roll pelletizing press that forms the pellets 9 from the biomass 1.

According to FIG. 2 the metering device 4 does not include a metering screw 19 but of a spreading device 6, which places or spreads the biomass 1 with the most uniform possible weight per unit area on a shaping belt 7. The biomass in a spreading device 6 is placed on the shaping belt 7 with different methods, in which the use of spreading rolls is preferred. Optimal loosening already occurs here and a looser positioning of the biomass 1 on an intermediate conveyor, the shaping belt 7. In a practical example the instruction of the embodiments already understands the spreading device 6 to be a combination of a metering and breaker device in the sense of one practical example. Advantageously the biomass 1 is now present in a uniform mat 8 and, depending on the width of the shaping belt, can be fed over an arbitrary width to an oversized pelletizing press 2 with uniform weight per unit area. A control or regulation device (not shown) is preferably provided, which ensures an optimal input of biomass 1 on the shaping belt 7 in the pelletizing press 2 as a function of possible production volume and speed of the roll press. Here again a steam treatment device 13 can be provided, which preferably passes steam through the shaping belt 7 and mat 8, in which case the shaping belt 7 is designed as a screen belt.

Advantageously the mat 8 can be examined on the shaping belt by means of an investigation device 11, preferably a radiation device to determine the weight per unit area of the mat 8 in order to determine irregularities in the biomass 1. For example, weight per unit area differences because of sand grains can be detected with a such a radiation device, since a high-resolution grid is possible and the weight per unit area difference of a sand grain, which was not removed by processing by screening or gravity separation, is detectable. A radiation device generally includes a transmitter and a receiver with evaluation unit, which sends the information to a control or regulation device that is connected to corresponding devices for the sorting out of foreign objects. In the case of a defect site in mat 8, this is disposed of in an ejection shaft 16 in which the shaping belt 7 changes the ejection area of the mat 8 through a shaping belt return 17. The ejected mat 8 is fed after a breaker device 5 before the biomass 1 enters the pelletizing press 2 and is compressed to pellets 9.

An enlarged view of the breaker device 5 is shown in FIG. 3, which includes at least one spoked roll 14 or spoke roll 14, here four spoked rolls 14. For improvement of loosening, at least one feed roll 15 can be provided in front of the spoked rolls 14 in the direction of fall; in this preferred practical example there are four feed rolls 15, which ensure pre-separation in steps. The direction of rotation of the spoked rolls is shown as an example. Guide flaps 18 can be arranged in the breaker device 5. The guide flaps 18 are preferably adjusted in angle toward the wall of the breaker device 5 and/or rolls by means of control devices. The adjusted guide flaps 18 preferably occur in order to guide the stream of falling biomass 1 and adjust the contact angle of the biomass 1 against the feed rolls 15 and/or the breaker rolls.

FIG. 4 shows an enlarged view of another variant of the breaker device 5, which is arranged on a shaping belt 7 according to FIG. 2. A milling roll 10 with appropriate speed then rotates clockwise in the drawing and directly separates the mat 8 at the end of the metering device 4. Such a milling roll 10 can also preferably be arranged in the discharge area of a metering screw 19 and ensure separation of the biomass 1 during discharge from the metering screw 19. In all practical examples the biomass 1 is divided over a specified or given surface by the breaker device 5 and then fed uniformly to the pelletizing press 2. Only biomass 1 that is screened during processing to a size via a 0.3 mm mesh width is preferably used.

An enlarged side view of possible exemplary or variations of breaker rolls 14 or spoked rolls 14 is shown in FIG. 5, which have straight spokes 22 in the upper partial drawing, but which can also be scoop-shaped and/or bent. In the middle view the spokes 22 are shown as connections between the outer disks of the spoked roll 14, in which the connections are arranged in a radius and preferably includes connection tubes or rods. In the lower partial drawing the breaker roll 14 or the spoked roll 14 is provided with teeth 23. In a two-stage variant, especially according to FIG. 3, feed rolls 15 are arranged in front of the breaker rolls 14 or the spoked rolls 14 in the direction of fall of biomass 1. It is also naturally possible to use other loosening methods or devices in order to achieve the objective of proper loosening and/or distribution of the biomass 1 before or over a pelletizing press 2.

Another variant of a pelletizing press 2 is shown in FIG. 6, which includes a rotating annular die 24 and pan-grinder rollers 21 lying against it. In the particularly preferred variant a mat 8 is spread onto the shaping belt 7 and ejected above the pelletizing press 2 via a preferably equal length of the annular die 24 or pan-grinder rollers 21. The mat 8 broken up during ejection or falling is then loosened by at least one breaker roll, in the present example four spoked rolls 14 and uniformly distributed over the distribution zone 20. At particularly high throughputs or in other applications it can be necessary to design the breaker device 5 in two stages. For example, the mat 8 can be compacted on the shaping belt 7 for optimization of subsequent treatments with a preliminary press 12, for example, for a steam treatment device 13 or an optimized examination device 11 or examination device 11. For this purpose feed rolls 15 are provided in front of the breaker rolls in the direction of fall of biomass 1, which are adapted to the application and have similar design geometries to the spoked rolls 14 according to FIG. 5. One or more screens 25 can also be arranged in the breaker device 5 as an alternative to guide flaps 18.

Since distribution has already occurred by the produced uniform mat preferably optimized in weight per unit area in the longitudinal extent of pelletizing press 2, the mat 8 is now distributed roughly over the diameter or over the distribution zone 20 and simultaneously loosened homogeneously so that no interfering separations of fine and coarse product or agglomerations reach the compression area of the pelletizing press 2. It is clear that the breaker device 5 can loosen the spread mat 8 according to FIGS. 2 and 6 independently of the advance of the shaping belt 7, the height of the mat 8 or also the density of the mat 8. This is especially true, if the biomass 1 has a tendency toward sticking because of steam treatment and/or water spraying beforehand.

EXEMPLARY EMBODIMENTS

According to a first embodiment, a method for the production of pellets 9 from processed biomass 1 in a pelletizing press 2 for use as fuel in furnaces, in which the biomass 1 includes cellulose- and/or lignocellulose-containing fibers, shavings or chips with or without a binder and/or additives and the biomass 1 after processing is fed with a metering device 4 to a pelletizing press 2, characterized by the fact that the biomass 1 is separated directly before the pelletizing press 2 with a breaker device 5.

According to a second embodiment, a method for the production of pellets 9 from processed biomass 1 in a pelletizing press 2 for use as fuel in furnaces, in which the biomass 1 includes cellulose- and/or lignocellulose-containing fibers, shavings or chips with or without a binder and/or additives and the biomass 1 after processing is fed with a metering device 4 to a pelletizing press 2, especially according to the first embodiment, characterized by the fact that the biomass 1 is introduced to a metering device 4 including a spreading device 6 and an endless shaping belt 7 lying beneath it in the direction of fall, in which a mat 8 with an essentially uniform weight per unit area is formed on the shaping belt 7 in the metering device 4 and the metering device 4 feeds the mat 8 to a breaker device 5 in front of the pelletizing press 2 in which the biomass 1 is separated by the breaker device 5.

According to a third embodiment, a method according to the first embodiment or the second embodiment, characterized by the fact that the biomass 1 is divided over a specified surface by the breaker device 5.

According to a fourth embodiment, a method according to one or more of the preceding embodiments, characterized in the fact that breaker device 5 uses at least one spoked roll 14.

According to a fifth embodiment, a method according to one or more of the preceding embodiments, characterized by the fact that the breaker device 5 divides the biomass 1 with a milling roll 10 during discharge from the metering device 4.

According to a sixth embodiment, a method according to one or more of the preceding embodiments, characterized by the fact that the biomass 1 is checked by means of an examination device 11, especially with a radiation device, for defective sites and on recognition of such sites the mat 8 is transferred in sections to an ejection shaft 16.

According to a seventh embodiment, a method according to one or more of the preceding embodiments, characterized by the fact that the biomass 1 is used which is screened during processing to a size above 0.3 mm (mesh width).

According to an eighth embodiment, a method according to one or more of the preceding embodiments, characterized by the fact that the biomass 1 is traversed in the metering device 4 with steam in a steam treatment device 13.

According to a ninth embodiment, a method according to one or more of the preceding embodiments, characterized by the fact that the mat 8 is compacted in the metering device 4.

According to a tenth embodiment, a method according to one or more of the preceding embodiments, characterized by the fact that an extruder press, a two-roll press or an annular die with at least one pan-grinder roller arranged on the inside or outside is used as a pelletizing press 2.

According to an eleventh embodiment, an installation for the production of pellets 9 from processed biomass 1 in a pelletizing press 2 for use as fuel in furnaces, in which the biomass 1 includes cellulose- and/or lignocellulose-containing fibers, shavings or chips with or without a binder and/or additives and a metering device 4 is arranged for the pelletizing press 2, characterized by the fact that for the separation of the biomass 1 a breaker device 5 is arranged in front of the pelletizing press 2 in the direction of production.

According to a twelfth embodiment, an installation for the production of pellets 9 from processed biomass 1 in a pelletizing press 2 for use as fuel in furnaces, in which the biomass 1 includes cellulose- and/or lignocellulose-containing fibers, shavings or chips with or without a binder and/or additives, in which for storage of the biomass 1 after preparation a biomass bunker 3 is arranged and for discharge of the biomass 1 from the biomass bunker 3 a metering device 4 for the pelletizing press 2 is arranged, especially according to the eleventh embodiment, characterized by the fact that a spreading device 6 is arranged as a metering device 4 for the formation of a mat 8 with an essentially uniform weight per unit area and an endless shaping belt 7 lying beneath it is arranged in the direction of fall and that a breaker device 5 is arranged for the separation of the biomass 1.

According to a thirteenth embodiment, an installation according to the eleventh embodiment or the twelfth embodiment characterized by the fact that at least one spoke roll 14 is arranged as a breaker device 5 in the direction of fall of the biomass 1 after emergence from the metering device 4.

According to a fourteenth embodiment, an installation according to one or more of the eleventh embodiment to the thirteenth embodiment, characterized by the fact that a milling roll 10 is arranged at the output of the metering device 4 as breaker device 5 for the separation of the biomass 1.

According to a fifteenth embodiment, an installation according to one or more of the eleventh embodiment to the fourteenth embodiment, characterized by the fact that an examination device 11, especially a radiation device, is arranged in the metering device 4 to check the biomass 1.

According to a sixteenth embodiment, an installation according to one or more of the eleventh embodiment to the fifteenth embodiment, characterized by the fact that a steam treatment device 13 is arranged in the metering device 4 to pass steam through the biomass 1.

According to a seventeenth embodiment, an installation according to one or more of the eleventh embodiment to the sixteenth embodiment, characterized by the fact that a metering screw 19 or preliminary press 12 is arranged in the metering device 4 to compact the biomass 1.

According to an eighteenth embodiment, an installation according to one or more of the eleventh embodiment to the seventeenth embodiment, characterized by the fact that an extruder press, a two-roll press or an annular die with at least one pan-grinder roller arranged on the inside or outside is arranged as a pelletizing press 2.

The construction and arrangement of the installation, as shown in the various exemplary embodiments, is illustrative only. Although some embodiments have been described in detail in this disclosure, many modifications are possible without materially departing from the novel teachings and advantages of the subject matter described herein. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present disclosure. 

1. A method for producing pellets from processed biomass in a pelletizing press for use as fuel in furnaces, comprising the steps of: processing the biomass, wherein the biomass includes cellulose- and/or lignocelluloses-containing fibers, shavings, or chips; feeding the biomass to the pelletizing press with a metering device; and separating the biomass with a breaker device directly before feeding the biomass to the pelletizing press.
 2. The method of claim 1, further comprising: introducing the biomass to the metering device, wherein the metering device includes a spreading device and an endless shaping belt positioned below the spreading device and in a direction in which the biomass falls; forming a mat having an essentially uniform weight per area; and feeding the mat to the breaker device positioned in front of the pelletizing press.
 3. The method of claim 1, further comprising dividing the biomass over a specified surface using the breaker device.
 4. The method of claim 1, wherein the breaker device includes at least one spoked roll.
 5. The method of claim 1, further comprising dividing the biomass, during discharge of the biomass from the metering device, using a milling roll included in the breaker device.
 6. The method of claim 2, further comprising: checking the mat with an examination device for defective sites; and transferring the defective sites of the mat in sections to an ejection shaft upon recognizing the defective sites in the mat, wherein the examination device includes a radiation device.
 7. The method of claim 1, further comprising screening the biomass during processing to a mesh width size above 0.3 mm.
 8. The method of claim 1, further comprising traversing the biomass in the metering device with steam using a steam treatment device.
 9. The method of claim 2, further comprising compacting the mat in the metering device.
 10. The method of claim 1, further comprising using as the pelletizing press an extruder press, a two-roll press, or an annular die having at least one pan-grinder roller arranged on an inside or an outside of the annular die.
 11. An installation for production of pellets from processed biomass for use as fuel in furnaces, in which the biomass includes cellulose- and/or lignocelluloses-containing fibers, shavings, or chips, the installation comprising: a pelletizing press; a metering device arranged for the pelletizing press; and a breaker device arranged in front of the pelletizing press in a direction of production, wherein the breaker device is configured to separate the biomass.
 12. The installation of claim 11, wherein a metering device includes a spreading device configured to form a mat having an essentially uniform weight per unit area; the installation further comprising an endless shaping belt positioned below the spreading device in a direction in which the biomass falls.
 13. The installation of claim 11, wherein the breaker device includes at least one spoke roll positioned in a direction in which the biomass falls located after the biomass emerges from the metering device.
 14. The installation of claim 11, wherein the breaker device includes a milling roll arranged at an output of the metering device.
 15. The installation of claim 11, further comprising an examination device arranged in the metering device to check the biomass, wherein the examination device includes a radiation device.
 16. The installation of claim 11, further comprising a steam treatment device included in the metering device and configured to pass steam through the biomass.
 17. The installation of claim 11, further comprising a metering screw or a preliminary press included in the metering device and configured to compact the biomass.
 18. The installation of claim 11, wherein the pelletizing press includes: an extruder press, a two-roll press, or an annular die having at least one pan-grinder roller arranged on an inside or an outside of the annular die. 